Steam generator



FIG. 1 is a front perspective view of a steam generator showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a top view thereof.

The oblique shade lines on the top surface represent a transparent or translucent surface. The broken lines within the shaded area represent features that form no part of the claimed design and form no part thereof. The broken lines depicting the remainder of the steam generator form no part of the claimed design. 

CLAIM The ornamental design for a steam generator, as shown and described. 